Conventional utility networks supply utilities for commercial, residential and industrial purposes. Regularly supplied utilities include, for example, water, air, gas, electricity, and steam, which are collectively designated by the acronym WAGES. In a typical electrical distribution system, for example, electrical energy is generated by an electrical supplier or utility company and distributed to consumers via a power distribution network. The power distribution network is often a network of electrical distribution wires (more commonly known as “electrical transmission lines”) which link the electrical supplier to its consumers. Additional devices, such as bus bars, switches (e.g., breakers or disconnectors), power transformers, and instrument transformers, which are typically arranged in switch yards and/or bays, are automated for controlling, protecting, measuring, and monitoring substations.
Typically, electricity from a utility is fed from a primary station over a distribution cable to several local substations. At the local substations, the supply is transformed by distribution transformers from a relatively high voltage on the distributor cable to a lower voltage at which it is supplied to the end consumer. From the local substations, the power is provided to industrial users over a distributed power network that supplies power to various loads. Such loads may include, for example, various power machines, lighting systems, HVAC systems, security systems, etc.
Within many power distribution networks, monitoring devices are being incorporated into more sophisticated and complex monitoring systems. Such devices include revenue meters, power quality meters, protection relays, programmable logic controllers, remote terminal units, contactors, cameras, etc. Monitoring systems often include devices installed at key points within the system's architecture for monitoring and/or protection of various loads, generators, substations, mains, etc. No longer stand-alone, many embedded electrical devices work in conjunction with other devices (hardware and/or software) and associated equipment.
While utilizing device interconnectivity and complexity can reduce work effort and minimize operating costs, it can also present certain problems. The impact of such problems is best appreciated by first understanding the overall time and effort required to setup such a system during the commissioning of the system. System commissioning, wherein all of the devices and components are installed, configured, and setup to operate, is generally very complex, time consuming, and expensive. Traditionally, many, if not all, of the devices must be individually configured with information that is relevant to the user's needs for the specific point within the system architecture where this device is installed. By way of example, the device may be configured to note it is connected to a feeder, generator, service entrance, or other subcomponent. In addition, the device may contain a notation of the type of measurement being taken, the communication protocols being used, the internet protocol (IP) address and/or other associated configurations, the trip setpoints and curves for a protection relay, etc. Moreover, each device may have custom firmware or special notations from the end user that are noted during the commissioning process. Often, these devices are also configured to connect to a software monitoring package, such as, for example, Building Automation Control Software or Energy Management Software.
With the reduction of analog and mechanical counters, many energy devices now digitally measure the monitoring and protection information, and store such information locally on the device itself. Generally, the more information that can be collected and stored, the more useful that compilation of information is for subsequent analysis. In some cases, the information is stored (or “logged”) and later accessed and transferred by the user; in other cases, the information is transferred over a network to a software monitoring package or system. In both cases, however, there are limitations on the device (physical device or software) when the logged data fills the local memory (storage capacity).
In some cases, a piece of hardware or software in the system may fail. For instance, a specific hardware device could break down, which generally requires a new device be commissioned and configured to have the same characteristics as the failed device. This typically requires downtime of the power system, or significant sections thereof, while the new device is manually installed and setup. This can be very costly to the user as downtime of an electrical system could equate to penalties from their customers, loss of production and, thus, loss of profit, etc.
It is also problematic when a device is logging information, but the device memory (storage capacity) becomes full. If there is no alternative way to transfer or otherwise store the data, the subsequently collected information can be lost. This can be costly, as the lost information can be critical to the user if, for example, such information is billing data on a revenue based meter. Simply adding more memory space (storage capacity) to the device does not always solve the foregoing problem, particularly when the added memory in some devices is not fully utilized. By way of example, in cases where there is a huge trip or sag/swell/transient in the system, the corresponding device or devices will do high speed logging of the event, which can use a considerable amount of device memory. It is difficult to predict which device will capture such unpredictable events; thus, the added memory of some devices will remain mostly unused, and just record simple interval data or other information on a regular basis (e.g., every 15 minutes). Moreover, if such an event never occurs, the extra logging memory is wasted. In addition, adding more memory space across all devices in the system can be very expensive, as this will typically require service personnel to implement, and possibly a device being placed out of commission. As well, different devices in the system may be commissioned with complex frameworks or firmware, which in turn uses up more memory and processing power. In general, the actual “free” memory for a particular device is not accurately known until the device is commissioned and installed.
It is also a problem when the system's monitoring software fails. In this case, the interconnectivity and partial setup information of the networked devices can be lost with the software failure. This may require the entire system be re-commissioned. Although a one-time job, the re-commissioning of such devices can last up to a week for small projects, whereas for larger projects it could last many months or even up to a year. As previously mentioned, downtime of this nature due to failure of a working system can be catastrophic for a user.